My car will not start

I was going down the road about forty five mph and I heard something but could not figure out what it was. Then about a mile down the road I lost all power steering, all power the car shut of. So I pulled over looked under hood and both of my belts had just came off. They did not break they just popped off. So it took about two or three hours to finally get belts back on car. I then tried to crank car back up and it threw one of the belts off again as soon as I tried to turn it over. So I had someone who I thought could fix my car and all they did and said to me is they put the belts on, but car will not crank. And that they did not know what was wrong. When I try crank the car all it does is roll over (if I am saying that right). I know when it is trying to be cranked both belts are turning. I think it could be my crank pulley because it looks like it it is moving way too much. But I do not know. I was told that it jumped time. I just do not want to believe it jumped time because of the crank pulley moving the way it does. It just seems like it would need to be replaced, but if it does do I have to get a whole crankshaft or just a pulley? What parts would I need to get? I just really need my car fixed. Please help me.